OBJECTIVES: 1. The further characterization of the chromatin of the fungus Aspergillus nidulans; 2. A study of the in vivo and in vitro assembly of chromatin under physiological conditions. A possible role for DNA methylation in assembly will be tested. BIBLIOGRAPHIC REFERENCE: Marinus, M.G., Morris, N.R., Soll, D., Kwong, T.C., Isolation and partial characterization of three Escherichia coli mutants with altered transfer ribonucleic acid methylase. J. Bact., 122, 257 (1975); Marinus, M.G., Morris, N.R., Pleiotropic effects of a DNA adenine methylation mutation (dam-3) in Escherichia coli K12. Mut. Res., 28, 15 (1975).